I have T-Mobile and use it in Europe. But on many occasions, the data is very slow. This is especially true for directions.
Since I have a dual SIM phone I'm thinking of getting a European sim for the second slot. This will be mostly for data.
Are there any sim cards I can load for voice and data that don't expire or are valid for more than one month?
Being able to buy it in London would be a plus.
The Vodafone UK SIM that I'm using does not expire as long as you use it for a chargeable activity (e.g., send a text) at least every 6 months.
I bought mine on EBay, but you could surely buy it at a Vodafone store, and likely at any Car Phone Warehouse, in London.
I like O2 and it's easy to keep their SIMs active.
Regarding the perception that cellular data service is slow with any particular carrier, double-check whether your plan subjects you to "throttling" (speed reduction after you've used a certain amount of data), and whether your phone supports all (or as many as possible) of the LTE bands that your carrier uses in the countries you are visiting. Use of the radio frequency spectrum has been evolving rapidly over the past year or two, and changes will continue. If your phone is a few years old, replacing it during this model year or the next might be beneficial. Check detailed specifications online and match the exact part number on the phone's box. Apple, for example, has simultaneously offered multiple versions of the iPhone in the US, with slight differences in LTE band lineups.
Re: buying in London, enjoy free roaming while it lasts! Now that Boris has a solid majority, Brexit is back on. Post-Brexit, the EU rule that forbids carriers from charging for roaming won't apply to UK SIMs used in EU countries, or to EU SIMs used in the UK.
Pay-as-you-go SIM cards only expire if you don't use them. If you use them every month they stay valid forever.
Just make a 5 second call to your own home number, or go to a website every week.
If you don't use them, they give the phone number to somebody else.
Both my Italian Tim sim and Belgian Orange sim only require top ups yearly. I think I've had the Tim sim for about ten years; the Belgian Orange sim for three years. I top them at arrival and then again just before departure. It helps that we visit these countries annually. I have not registered them online, so do the top ups personally. I also have T-Mobile and seriously considering letting these sims expire or possibly just keeping one active. T-Mobile service includes free texting worldwide and charges $0.25 per minute for international use plus free slow data for international use.
Regarding Brexit, Vodafone UK and several other providers have publicly stated that they will not charge roaming in the EU, post Brexit. Of course, that could change.
Post-Brexit, the EU rule that forbids carriers from charging for roaming won't apply to UK SIMs used in EU countries, or to EU SIMs used in the UK.
Not necessarily. The UK could negotiate a separate agreement to be part of this roaming group as for example Norway has.
It is definitely a possibility though.
If you'd rather just use your T-Mobile SIM card, they do have plans that will speed up your data service, but they are pretty pricey. See https://www.t-mobile.com/news/simple-global-data-passes.
